Gestalt
Proximity
Close elements seem to be a group.
Closure
Human brain ignores gaps and tries to understand the bigger context.
Similarity
Similarly looking elements seem to be a group.
Common region
Elements which are close together seem to be a group.
Continuity
Elements which are ordered in a line or curve seem to be a group.
Figure & ground
Human brain recognizes if something is in the fore- or background.
Symmetry
Symmetric elements give the human brain the feeling that everything is ordered.
Common fate
Elements which move in the same direction seem to be a group.
Law of Prägnanz
The way we group elements together to form a perceptual whole.